Classic chess rules

Touch-move rule

In serious play, if a player having the move touches one of his pieces as if having the intention of moving it, then he must move it if it can be legally moved. So long as the hand has not left the piece on a new square, the latter can be placed on any accessible square. If a player touches one of the opponent's piece then he must capture that piece if it can be captured. If none of the touched pieces can be moved or captured there is no penalty (Schiller 2003:19–20).

When castling, the king must be the first piece touched. If the player touches his rook at the same time as touching the king, he must castle with that rook if it is legal to do so. If the player completes a two-square king move without touching a rook, he must move the correct rook accordingly if castling in that direction is legal. If a player starts to castle illegally, another legal king move must be made if possible, including castling with the other rook (Schiller 2003:20).

When a pawn is moved to its eighth rank, once the player takes his hand off the pawn, it can no longer be substituted for a different move of the pawn. However, the move is not complete until the promoted piece is released on that square.

If a player wishes to touch a piece with the intention of adjusting its position on a square, he must first alert his opponent of his intention by saying "J'adoube" or "I adjust". Once the game has started, only the player whose turn it is to move may touch the pieces on the board (Schiller 2003:19–20).